diff --git a/compiler/lib/flow.ml b/compiler/lib/flow.ml
index df14ea4e50..8ce118f14a 100644
--- a/compiler/lib/flow.ml
+++ b/compiler/lib/flow.ml
@@ -401,24 +401,21 @@ let rec the_shape_of info x =
   get_approx
     info
     (fun x ->
-      if Var.ISet.mem info.info_possibly_mutable x
-      then Shape.Top "possibly_mutable"
-      else
-        match Shape.get x with
-        | Some shape -> shape
-        | None -> (
-            match info.info_defs.(Var.idx x) with
-            | Expr (Block (_, a, _, Immutable)) ->
-                Shape.Block (List.map ~f:(the_shape_of info) (Array.to_list a))
-            | Expr (Closure (l, _)) ->
-                Shape.Function { arity = List.length l; pure = false; res = Top "unk" }
-            | Expr (Special (Alias_prim name)) -> (
-                try
-                  let arity = Primitive.arity name in
-                  let pure = Primitive.is_pure name in
-                  Shape.Function { arity; pure; res = Top "unk" }
-                with _ -> Top "other")
-            | _ -> Shape.Top "other"))
+      match Shape.get x with
+      | Some shape -> shape
+      | None -> (
+          match info.info_defs.(Var.idx x) with
+          | Expr (Block (_, a, _, Immutable)) ->
+              Shape.Block (List.map ~f:(the_shape_of info) (Array.to_list a))
+          | Expr (Closure (l, _)) ->
+              Shape.Function { arity = List.length l; pure = false; res = Top "unk" }
+          | Expr (Special (Alias_prim name)) -> (
+              try
+                let arity = Primitive.arity name in
+                let pure = Primitive.is_pure name in
+                Shape.Function { arity; pure; res = Top "unk" }
+              with _ -> Top "other")
+          | _ -> Shape.Top "other"))
     (Top "init")
     (fun _u _v -> Shape.Top "merge")
     x
diff --git a/compiler/tests-full/stdlib.cma.expected.js b/compiler/tests-full/stdlib.cma.expected.js
index 92f9855753..013a1ecd10 100644
--- a/compiler/tests-full/stdlib.cma.expected.js
+++ b/compiler/tests-full/stdlib.cma.expected.js
@@ -305,7 +305,7 @@
 
 //# unitInfo: Provides: Stdlib
 //# unitInfo: Requires: CamlinternalFormatBasics
-//# shape: Stdlib:[F(1),F(1),N,N,N,N,N,N,N,N,N,N,N,N,N,F(2),F(2),F(1),N,N,F(1),N,N,N,N,N,N,F(2),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(2),N,N,N,F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(3),F(1),N,F(2),F(2),F(2),F(4),F(4),F(2),F(2),F(2),F(2),F(1),F(1),F(1),F(1),F(2),F(1),F(1),F(3),F(1),F(1),F(4),F(4),F(2),F(1),F(1),F(1),F(2),F(1),F(1),F(1),F(1),F(2),N,F(1),F(2),F(1),F(1),F(1),F(4),N,N]
+//# shape: Stdlib:[F(1),F(1),N,N,N,N,N,N,N,N,N,N,N,N,N,F(2),F(2),F(1),N,N,F(1),N,N,N,N,N,N,F(2),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(2),N,N,N,F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(1),F(3),F(1),F(1),F(2),F(2),F(2),F(4),F(4),F(2),F(2),F(2),F(2),F(1),F(1),F(1),F(1),F(2),F(1),F(1),F(3),F(1),F(1),F(4),F(4),F(2),F(1),F(1),F(1),F(2),F(1),F(1),F(1),F(1),F(2),N,F(1),F(2),F(1),F(1),F(1),F(4),F(1),N]
 (function
   (globalThis){
    "use strict";
@@ -1634,7 +1634,7 @@
 
 //# unitInfo: Provides: Stdlib__Seq
 //# unitInfo: Requires: CamlinternalLazy, Stdlib, Stdlib__Atomic, Stdlib__Lazy
-//# shape: Stdlib__Seq:[F(1),F(1),F(1),F(2),F(3),F(2),F(3),F(2),F(2),F(2),F(2),F(2),F(2),F(3),F(4),F(3),F(3),F(3),F(3),N,F(2),F(3),F(2),F(3),F(2),F(2),F(2),F(2),F(3),F(2),F(3),F(3),F(3),F(2),F(2),F(3),F(3),F(3),F(1),N,F(1),F(2),F(3),F(2),F(3),F(3),F(3),F(4),F(3),F(4),F(2),F(3),F(1),F(1),F(2),F(2),F(1),F(1),F(2)]
+//# shape: Stdlib__Seq:[F(1),F(1),F(1),F(2),F(3),F(2),F(3),F(2),F(2),F(2),F(2),F(2),F(2),F(3),F(4),F(3),F(3),F(3),F(3),F(1),F(2),F(3),F(2),F(3),F(2),F(2),F(2),F(2),F(3),F(2),F(3),F(3),F(3),F(2),F(2),F(3),F(3),F(3),F(1),N,F(1),F(2),F(3),F(2),F(3),F(3),F(3),F(4),F(3),F(4),F(2),F(3),F(1),F(1),F(2),F(2),F(1),F(1),F(2)]
 (function
   (globalThis){
    "use strict";
@@ -21372,8 +21372,7 @@
           ? empty_backtrace
           :  /*<<printexc.ml:331:4>>*/ caml_get_exception_raw_backtra(0);
        /*<<printexc.ml:345:4>>*/ try{
-        /*<<printexc.ml:345:9>>*/  /*<<printexc.ml:345:9>>*/ caml_call1
-        (Stdlib[103], 0);
+        /*<<printexc.ml:345:9>>*/ Stdlib[103].call(null, 0);
       }
       catch(_C_){}
        /*<<printexc.ml:346:4>>*/ try{
@@ -23038,7 +23037,7 @@
 
 //# unitInfo: Provides: Stdlib__Hashtbl
 //# unitInfo: Requires: Stdlib, Stdlib__Array, Stdlib__Atomic, Stdlib__Domain, Stdlib__Int, Stdlib__Random, Stdlib__Seq, Stdlib__String, Stdlib__Sys
-//# shape: Stdlib__Hashtbl:[N,N,N,N,F(3),F(2),F(2),F(2),F(2),F(2),F(3),N,N,N,N,F(1),F(1),F(2),N,N,N,N,F(2),F(2),F(1),F(1),F(1),F(1),F(2),F(3),F(4)]
+//# shape: Stdlib__Hashtbl:[F(2),F(1),F(1),F(1),F(3),F(2),F(2),F(2),F(2),F(2),F(3),F(2),F(2),F(3),F(1),F(1),F(1),F(2),F(1),F(1),F(1),F(1),F(2),F(2),F(1),F(1),F(1),F(1),F(2),F(3),F(4)]
 (function
   (globalThis){
    "use strict";
@@ -24079,7 +24078,7 @@
 
 //# unitInfo: Provides: Stdlib__Weak
 //# unitInfo: Requires: Stdlib, Stdlib__Array, Stdlib__Int, Stdlib__Obj, Stdlib__Sys
-//# shape: Stdlib__Weak:[F(1),N,N,F(2),F(2),F(2),F(4),F(5),F(1)]
+//# shape: Stdlib__Weak:[F(1),F(1),F(3),F(2),F(2),F(2),F(4),F(5),F(1)]
 (function
   (globalThis){
    "use strict";
@@ -24632,7 +24631,7 @@
 
 //# unitInfo: Provides: Stdlib__Format
 //# unitInfo: Requires: CamlinternalFormat, Stdlib, Stdlib__Array, Stdlib__Buffer, Stdlib__Bytes, Stdlib__Domain, Stdlib__Int, Stdlib__List, Stdlib__Queue, Stdlib__Seq, Stdlib__Stack, Stdlib__String
-//# shape: Stdlib__Format:[F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),N,F(1),F(3),F(2),F(3),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(1),F(3),F(2),F(3),F(2),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(2),F(1),F(2),F(1),N,F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(1),F(1),N,F(1),N,F(1),F(1),N,F(1),N,F(1),F(1),F(2),F(2),F(1),F(1),F(1),F(1),F(1),F(2),F(1),F(5),F(4),F(4),F(4),F(2),F(4),F(4),F(4),F(1),F(1),F(1),F(1),F(1),F(1),F(2),F(3),F(2),F(3),F(2),F(2)]
+//# shape: Stdlib__Format:[F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(3),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(1),F(3),F(2),F(3),F(2),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(2),F(1),F(2),F(1),N,F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(3),F(2),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(2),F(1),F(1),F(1),N,F(1),N,F(1),F(1),N,F(1),N,F(1),F(1),F(2),F(2),F(1),F(1),F(1),F(1),F(1),F(2),F(1),F(5),F(4),F(4),F(4),F(2),F(4),F(4),F(4),F(1),F(1),F(1),F(1),F(1),F(1),F(2),F(3),F(2),F(3),F(2),F(2)]
 (function
   (globalThis){
    "use strict";
@@ -28906,7 +28905,7 @@
 
 //# unitInfo: Provides: CamlinternalOO
 //# unitInfo: Requires: Stdlib, Stdlib__Array, Stdlib__List, Stdlib__Map, Stdlib__Obj, Stdlib__Sys
-//# shape: CamlinternalOO:[N,F(1),F(2),F(3),F(2),F(2),F(2),F(2),F(2),F(3),F(2),F(4),F(1),F(2),N,F(1),F(1),F(6),F(2),F(3),F(1),F(1),F(1),F(2),F(2),F(3),F(2),F(2),N,F(1)]
+//# shape: CamlinternalOO:[F(1),F(1),F(2),F(3),F(2),F(2),F(2),F(2),F(2),F(3),F(2),F(4),F(1),F(2),N,F(1),F(1),F(6),F(2),F(3),F(1),F(1),F(1),F(2),F(2),F(3),F(2),F(2),N,F(1)]
 (function
   (globalThis){
    "use strict";
@@ -33108,7 +33107,7 @@
 
 //# unitInfo: Provides: Stdlib__MoreLabels
 //# unitInfo: Requires: Stdlib__Hashtbl, Stdlib__Map, Stdlib__Set
-//# shape: Stdlib__MoreLabels:[[N,N,N,N,F(3),F(2),F(2),F(2),F(2),F(2),F(3),N,N,N,N,F(1),F(1),F(2),N,N,N,N,F(2),F(2),F(1),F(1),F(1),F(1),F(2),F(3),F(4)],[F(1)],[F(1)]]
+//# shape: Stdlib__MoreLabels:[[F(2),F(1),F(1),F(1),F(3),F(2),F(2),F(2),F(2),F(2),F(3),F(2),F(2),F(3),F(1),F(1),F(1),F(2),F(1),F(1),F(1),F(1),F(2),F(2),F(1),F(1),F(1),F(1),F(2),F(3),F(4)],[F(1)],[F(1)]]
 (function
   (globalThis){
    "use strict";